Generic versions of sildenafil, vardenafil and tadalafil are available. Some platforms have a digital pharmacy that ships the medication to your home, while others send an electronic prescription to your local pharmacy. It works for up to 36 hours. If you experience chest pain, dizziness, or nausea during sex, seek immediate medical help. A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow. This is important for your overall health and safety, as certain medications can negatively interact with each other or cause existing conditions to worsen. It may be difficult to remain firm despite wanting to have sex.Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes muscles . If you have erectile dysfunction (ED), your doctor may recommend that you take Viagra. It’s a prescription drug that’s used in adult males* with ED. With ED, you have trouble getting . According to price-comparison site test1.ru, generic Revatio will cost you as little as $ per pill, depending on where you fill your prescription. That’s compared with .